A great variety of cleaning compositions have been described in the art. A problem associated with common cleaning compositions, when used in laundry application to treat different kinds of fabrics, including cotton and synthetic fabrics such as polyesters, polyamides and the like, is that they do not deliver an effective performance satisfactorily meeting consumer's needs, on all types of stains including greasy stains, enzymatic stains, mud/clay stains and the like.
It is thus an object of the present invention to provide overall improved stain removal performance on a wide range of stains while delivering excellent bleaching performance.
It has now been found that this object can be met by bleaching fabrics with a liquid composition comprising a peroxygen bleach and a solvent system comprising a hydrophobic solvent, i.e., a solvent having a hydrophilic index of less than 18, and a hydrophilic solvent, i.e., a solvent having a hydrophilic index of more than 18, wherein the hydrophilic index is defined by the following equation: ##EQU1## Indeed, it has been found that liquid compositions comprising a peroxygen bleach and such a solvent system, when used in a laundry operation, boost the removal of various types of stains including greasy stains, mud/clay-containing stains, enzymatic stains, as well as bleachable stains.
An advantage of the present invention is that excellent performance is provided in a variety of laundry applications, e.g., laundry detergent, or laundry additive, and preferably laundry pretreater.
In a preferred embodiment of the present invention the liquid compositions used herein may also comprise a bleach activator, which will react in an aqueous medium with hydrogen peroxide to form the corresponding peracid. It has been observed that this peracid is more effective at lower temperatures, e.g., at those temperatures where the pretreatment operation is usually performed (20.degree. C.-25.degree. C.), and thus allows the compositions herein to deliver more effective bleaching performance across a wider range of temperatures.
Another advantage of a particular embodiment of the present invention is that when such a solvent system, as described herein, is added in a liquid bleaching composition of the present invention formulated as an emulsion or a microemulsion, the viscosity of said composition is reduced, whatever the viscosity was before the addition of said solvent system. Thus, in one embodiment the present invention also provides liquid emulsions or microemulsions comprising a peroxygen bleach and a solvent system, as described herein, wherein the viscosity can be conveniently controlled while maintaining adequate physical stability, without the need to add any viscosity control agent which would raise the formula cost, and add bulk to the compositions without contributing to the bleaching/cleaning performance of said compositions.
EP-A-126545 discloses liquid scouring cleaners comprising an abrasive, at least 0.1% of terpene (e.g., d-limonene), at least 0.1% of benzyl alcohol and optionally surfactants, builders and the like. The compositions clean both greasy and particle soils from hard surfaces. No bleaches are disclosed. No laundry application is disclosed.
EP-A-216416 discloses liquid scouring cleansers (pH 8-12) with paraffin sulfonate and alkyl benzene sulfonate, 0.5%-10% of a mono- or sesquiterpene, 0.5%-3% of a polar solvent, an acrylic polymeric thickener, an abrasive and a viscosity enhancing compound. No bleaches are disclosed. No laundry application is disclosed.
EP-A-137616 discloses laundry liquid compositions formulated in the form of an emulsion having a pH of 6.5 or above and comprising at least 5% by weight of solvents. Such solvents include terpene and terpenoid solvents (e.g., pinene, d-limonene) as well as other solvents like benzyl alcohol, n-hexanol, paraffins. Mixtures of orange terpenes and benzyl alcohol are especially suitable for removing certain types of stains like dirty motor oil. The addition of non-polar solvents like benzyl alcohol, n-hexanol, mixed fatty alcohols, increases the stability. Pretreating of fabrics and through the wash treatment with such compositions are disclosed. No bleaches are disclosed.